Hypobaric chambers can achieve similar effects on the blood hemoglobin and hematocrit levels as living at altitude. The caveat is that you increase your chances of becoming polycythemic or having an abnormally high hemoglobin and hematocrit. If you get dehydrated in this state life threatening or crippling results can occur including heart attack or stroke. If you choose to go the route of getting a hypobaric chamber, talk with your doctor first and get periodic monitoring of your hemoglobin and hematocrit. You should not allow your hemoglobin to exceed 16.5 or your hematocrit exceed 50%. You still have to combine a well designed training program to develop your muscles, endurance, sprinting and aerobic threshold levels.

Lennard Zinn did a nice review in VeloNews a couple years ago on hypobaric chambers and there short comings. They are claustrophobic, not inductive to marital bliss, cumbersome, are expensive, have potential for failure due to mechanical problems and have to be used consistently to achieve an effect on raising your hematocrit. It might be cheaper and easier to get a job transfer to somewhere in the Rockies or the Himalayas than to consistently use one of these devices in the real world of a working, racing stiff.